Hunt L W, Gleich G J, Ohnishi T, Weiler D A, Mansfield E S, Kita H, Sur S
Division of Allergic Diseases and Medicine, Mayo Clinic, Rochester, Minnesota.
Am J Respir Crit Care Med. 1994 Jun;149(6):1471-5. doi: 10.1164/ajrccm.149.6.8004300.
Segmental bronchoprovocation (SBP) with allergen was used in an attempt to study eosinophils recruited to the airway 24 h after challenge. Unexpectedly, in the first four patients, neutrophils (rather than eosinophils) were recruited in the bronchoalveolar lavage (BAL) fluids, and we hypothesized that the allergen extracts were contaminated with endotoxin. The extracts used for challenge in the first four patients tested positive for bacterial endotoxin in a limulus amebocyte lysate assay. Rechallenge of one patient from the first group with a comparable dose of an endotoxin-free extract and SBP with endotoxin-free extract in five additional patients resulted in preferential recruitment of eosinophils rather than neutrophils. The number of neutrophils recovered from the challenged segments in the patients challenged with endotoxin-free extract was significantly less than that observed in the first four patients. Taken together, these observations suggest that neutrophil recruitment in the 24-h BAL fluids from the first four patients was probably due to endotoxin contamination of the allergen extract. We caution investigators that endotoxin contamination of allergen extract may alter the cellular inflammation during the late airway response following allergen challenge.
采用变应原进行节段性支气管激发试验（SBP），试图研究激发后24小时募集到气道的嗜酸性粒细胞。出乎意料的是，在前四名患者中，支气管肺泡灌洗（BAL）液中募集到的是中性粒细胞（而非嗜酸性粒细胞），我们推测变应原提取物被内毒素污染。在前四名患者中用于激发试验的提取物在鲎试剂检测中细菌内毒素呈阳性。第一组中的一名患者再次接受相当剂量的无内毒素提取物激发试验，另外五名患者接受无内毒素提取物的SBP试验，结果显示嗜酸性粒细胞而非中性粒细胞被优先募集。接受无内毒素提取物激发试验的患者中，从激发节段回收的中性粒细胞数量明显少于在前四名患者中观察到的数量。综上所述，这些观察结果表明，前四名患者24小时BAL液中的中性粒细胞募集可能是由于变应原提取物被内毒素污染所致。我们提醒研究人员，变应原提取物的内毒素污染可能会改变变应原激发后气道迟发反应期间的细胞炎症。
